From 038f2c09407ce86a7010c3a4cb035d8aff04058e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Beno=C3=AEt=20Legat?= <benoit.legat@gmail.com>
Date: Sat, 16 Mar 2024 08:07:35 +0100
Subject: [PATCH] Add key_type

---
 src/bases.jl | 6 ++++++
 src/types.jl | 4 ++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/bases.jl b/src/bases.jl
index e9d738f..2cd8fb0 100644
--- a/src/bases.jl
+++ b/src/bases.jl
@@ -14,6 +14,12 @@ Base.eltype(b::AbstractBasis) = eltype(typeof(b))
 Base.keytype(::Type{<:AbstractBasis{T,I}}) where {T,I} = I
 Base.keytype(b::AbstractBasis) = keytype(typeof(b))
 
+key_type(b) = keytype(b)
+# `keytype(::Type{SparseVector{V,K}})` is not defined so it falls
+# back to `keytype{::Type{<:AbstractArray})` which returns `Int`.
+key_type(::Type{SparseArrays.SparseVector{V,K}}) where {V,K} = K
+key_type(v::SparseArrays.SparseVector) = key_type(typeof(v))
+
 """
     ImplicitBasis{T,I}
 Implicit bases are not stored in memory and can be potentially infinite.
diff --git a/src/types.jl b/src/types.jl
index ca6d777..0a599e6 100644
--- a/src/types.jl
+++ b/src/types.jl
@@ -44,10 +44,10 @@ struct AlgebraElement{A,T,V} <: MA.AbstractMutable
 end
 
 function _sanity_checks(coeffs, A::AbstractStarAlgebra)
-    @assert keytype(coeffs) == keytype(basis(A))
+    @assert key_type(coeffs) == keytype(basis(A))
 end
 function _sanity_checks(coeffs::AbstractVector, A::AbstractStarAlgebra)
-    @assert keytype(coeffs) == keytype(basis(A))
+    @assert key_type(coeffs) == keytype(basis(A))
     @assert Base.haslength(basis(A))
     @assert length(coeffs) == length(basis(A))
 end